Sinéad O’Connor’s cause of death has been revealed one year after her tragic death … with her death certificate listing multiple respiratory issues, according to reports.

The Irish Independent reports O’Connor passed away from COPD — chronic obstructive pulmonary disease — exacerbated by bronchial asthma. She’d also been suffering from a respiratory tract infection, a contributory factor.

While British authorities announced back in January O’Connor passed from natural causes — no foul play suspected — we didn’t know the exact cause until this week.

As we told you … Sinéad was found unresponsive in her Southeast London apartment last year. Efforts were made to revive her, but it was too late.

O’Connor suffered from mental health issues for years … telling Dr. Phil she’d tried to take her own life at least eight times. Her 17-year-old son Shane committed suicide in early 2022 with Sinéad tweeting out she’d “Been living as an undead night creature since.”

However, it seems mental health ultimately played no role in her death.

Numerous stars — including Conor McGregor, Pink and Brandi Carlile — all paid tribute to the controversial singer in the weeks after her death. She was 56.

RIP